U.S. patent application number 13/201877 was filed with the patent office on 2012-02-16 for rotor section for a rotor of a turbomachine, and rotor blade for a turbomachine.
Invention is credited to Guido Ahaus, Alex Buschmann, Sascha Dungs, Harald Hoell, Karsten Kolk, Mirko Milazar, Peter Schroder, Vyacheslav Veitsman.
Application Number | 20120039719 13/201877 |
Document ID | / |
Family ID | 40635853 |
Filed Date | 2012-02-16 |
United States Patent
Application |
20120039719 |
Kind Code |
A1 |
Ahaus; Guido ; et
al. |
February 16, 2012 |
Rotor section for a rotor of a turbomachine, and rotor blade for a
turbomachine
Abstract
A rotor section for a rotor of a gas turbine, a rotor blade, and
a blocking element are provided. The rotor section includes a rotor
disk including rotor blades that are inserted thereon in holding
grooves and that are secured against sliding along the holding
grooves by means of a sealing element arranged at the end face. In
order to specify a reliable, simple, and easy-to-design
construction for the circumferential fixing of the sealing
elements, it is proposed that each sealing element be secured by
one blocking element, which engages in a hole arranged at the end
face in the rotor blade root.
Inventors: |
Ahaus; Guido; (Essen,
DE) ; Buschmann; Alex; (Essen, DE) ; Dungs;
Sascha; (Wesel, DE) ; Hoell; Harald;
(Wachtersbach, DE) ; Kolk; Karsten; (Mulheim a.d.
Ruhr, DE) ; Milazar; Mirko; (Oberhausen, DE) ;
Schroder; Peter; (Essen, DE) ; Veitsman;
Vyacheslav; (Gelsenkirchen, DE) |
Family ID: |
40635853 |
Appl. No.: |
13/201877 |
Filed: |
January 27, 2010 |
PCT Filed: |
January 27, 2010 |
PCT NO: |
PCT/EP2010/050934 |
371 Date: |
October 26, 2011 |
Current U.S.
Class: |
416/220R |
Current CPC
Class: |
F01D 5/3015 20130101;
F01D 5/081 20130101; Y02T 50/60 20130101; F01D 5/326 20130101; F01D
5/323 20130101 |
Class at
Publication: |
416/220.R |
International
Class: |
F01D 5/32 20060101
F01D005/32; F01D 5/30 20060101 F01D005/30 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 17, 2009 |
EP |
09002223.7 |
Claims
1.-11. (canceled)
12. A rotor section for the rotor of a turbomachine, comprising: a
plurality of rotor blade retaining grooves disposed on an outer
periphery of the rotor which extend in an axial direction of the
rotor and in which a rotor blade is arranged in each case, the
rotor blade including a blade root which corresponds to the rotor
blade retaining groove; a plurality of radially inwardly pointing
contact surfaces which are provided in each case on the rotor
blades; and a plurality of plate-like sealing elements, wherein for
the guiding of a cooling medium along a rotor surface on an end
face, the plurality of plate-like sealing elements bear against the
contact surface by centrifugal force action, wherein for securing
the plurality of sealing elements against displacement in a
circumferential direction at least one of the plurality of sealing
elements includes an opening provided in the sealing element for
accommodating a blocking element, wherein provision is made for a
hole, which aligns with the opening, and for a positionally secured
blocking element, which fits in the hole and in the opening,
wherein the hole is arranged in the blade root, and in that the
opening is of a keyhole-like design, and wherein the blocking
element is of a bolt-like design including a cam which is arranged
on an outer circumference of the blocking element, which cam may be
rotated between the blade root and the sealing element.
13. The rotor section as claimed in claim 12, wherein the hole is
arranged in each case closer to the radially inwardly pointing
contact surface and the opening is arranged closer to an edge of
the sealing element which bears against the contact surface of the
rotor blade than to an inner edge of the sealing element.
14. The rotor section as claimed in claim 12, wherein the blocking
element includes a crenellation on the end face, which may be bent
into a bit recess of the keyhole-like opening.
15. The rotor section as claimed in claim 14, wherein the
crenellation is part of an end-face ring of the blocking
element.
16. The rotor section as claimed in claim 12, wherein which the
blocking element is secured against loss by means of a Z-shaped
locking plate, a first end of which lies between the sealing
element and a further end face of the blade root.
17. The rotor section as claimed in claim 12, wherein the blocking
element includes an end-face opening for its removal.
18. The rotor section as claimed in claim 12, wherein the plurality
of sealing elements, bearing against each other in the
circumferential direction, form a sealing ring which fits in an
annular groove, which annular groove is provided on a
circumferential surface which is arranged on an end-face side
surface of the rotor.
19. A rotor blade for a turbomachine, comprising: an inverted
T-shaped or fir tree-shaped blade root, adjoining which are a
platform and an aerodynamically curved blade airfoil thereupon; and
a projection which protrudes over the blade root, wherein on an
underside of the projection facing the blade root provision is made
for a contact surface, facing the blade root, for a plate-like
sealing element, and wherein provision is made directly adjacent to
the projection for a hole, which is formed as a blind hole, in an
end face of the blade root for accommodating a blocking
element.
20. The rotor blade as claimed in claim 19, wherein the hole is
arranged closer to the projection than to an underside of the blade
root.
21. The rotor blade as claimed in claim 19, wherein the contact
surface is formed at least partially as a base of a groove which is
open towards the blade root.
22. The rotor blade as claimed in claim 19, wherein the projection
is formed as part of the platform or as part of a sideways
projecting sealing wing.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the US National Stage of International
Application No. PCT/EP2010/050934, filed Jan. 27, 2010 and claims
the benefit thereof. The International Application claims the
benefits of European Patent Office application No. 09002223.7 EP
filed Feb. 17, 2009. All of the applications are incorporated by
reference herein in their entirety.
FIELD OF INVENTION
[0002] The invention refers to a rotor section according to the
preamble of the claims. The invention furthermore refers to a rotor
blade according to the preamble of the claims.
BACKGROUND OF INVENTION
[0003] An axial rotor section according to generic type for a
turbine or a turbine rotor is known from laid open specification DE
1 963 364, for example. The rotor section, which comprises a rotor
disk, has on its outer periphery a plurality of axially extending
retaining grooves for rotor blades of the turbine. On the rotor
disk, on the end face, provision is made in this case for an
endlessly encompassing locating slot for sealing strips. On one
side wall of the locating slot, provision is made for a plurality
of projections which are evenly distributed in the circumferential
direction and partially overlap the base of the locating slot.
Seated in the locating slot are plate-like sealing strips which on
their radially inwardly disposed inner edge have a thickened
portion on both sides, the width of which corresponds approximately
to the width of the locating slot. The thickened portion, as seen
in the circumferential direction, in this case is sectionally
interrupted by recesses which are of a broad design corresponding
to the projections of the locating slot. As a result of this, the
sealing strip can be inserted in the locating slot by means of a
purely radial movement from the outside and after a displacement in
the circumferential direction--the displacement travel of which
corresponds approximately to the width of the projection--is hooked
into this. The thickened portion of the sealing strip then fits
behind the projections of the locating slot so that the sealing
strip cannot move outwards. For installing all the sealing strips,
these are to be inserted successively in the locating slot and only
then are to be collectively displaced in the circumferential
direction. As a result of this, the necessity of a sealing strip
lock is avoided. After inserting the sealing strips and the rotor
blades, the outer edges of the sealing strips are inserted in
platform-side grooves in the rotor blades so that the last-named
are secured against axial displacement. For finishing the
installation, the sealing strips are fixed in their raised position
by means of a screw. Each widened portion then bears against the
projection. By means of this arrangement of the components, a first
space which lies between the sealing strip and the end face of the
rotor disk can be separated and sealed in relation to a second
space, which lies on the other side of the sealing strip, for the
guiding of various media. For achieving a particularly satisfactory
seal, the sealing strip bears by its widened portion against that
sidewall of the locating slot on which there is no provision for a
projection. Moreover, an inner, conically extending edge of the
projection ensures that the sealing strip is pressed onto the
projection-less sidewall of the locating slot by influence of
centrifugal force.
[0004] One disadvantage of the known arrangement is the costly
construction of the side surfaces of the rotor disk and of the
sealing strip with projections and recesses. A further disadvantage
is the use of a screw for securing the sealing strip against
displacement in the circumferential direction. On account of the
alternating thermal stress which occurs between operation and
stationary state and on account of the hot gas which flows through
the turbine, problems relating to corrosion and strength in the
screw fastening can occur. These possibly cannot be resolved in a
specified manner. In this case, the screw is drilled out, wherein
this process is carried out as a rule on the rotor which still lies
in the lower casing half of the gas turbine. It can happen that
swarf falls into the lower casing half in the process, which can
bring about undesirable contaminations during subsequent
operation.
[0005] Also, a security for rotor blades against axial
displacement, which rotor blades are retained by means of a plate
which is displaceable in the circumferential direction, is known
from FR 2 524 933. The arrangement which is shown therein, however,
is not suitable for sealing a space close to the disk in relation
to a space which exists on the other side of the plate.
[0006] Furthermore, a rotor sub-assembly of a turbine, which has a
one-piece sealing ring for the axial locking of rotor blades, is
known from laid open specification DE 30 33 768 A1. The one-piece
sealing ring of DE 30 33 768 A1 is hooked into the turbine disk in
the manner of a bayonet connection. To this end, projections and
recesses are arranged alternately both on the turbine disk and on
the sealing ring in a distributed manner along the circumference.
For installation, the sealing ring is located on the rotor disk,
wherein the recesses and projections lie opposite each other. By
means of a slight rotation of both parts, these can then be
mutually hooked into each other. On account of the integral
constructional form of the sealing ring, this, however, can only be
used in aircraft gas turbines since their turbines are assembled by
stacking in the axial direction. Stationary gas turbines, on the
other hand, are assembled from two casing halves which encompass
the completely installed rotor.
SUMMARY OF INVENTION
[0007] The object of the invention is therefore the provision of an
axial rotor section for a stationary gas turbine and the provision
of a rotor blade of a turbine, which is further improved with
regard to the installation and removal of sealing elements.
[0008] The object which is directed towards the rotor section is
achieved by means of a rotor section according to generic type with
the features of the claims. Furthermore, the object which is
directly towards the rotor blade is achieved with a rotor blade
according to the claims.
[0009] The invention is based on the knowledge that a particularly
reliable securing of the sealing elements is especially possible
when the location at which the sealing elements are supported
against the rotor by centrifugal force and that location at which
the individual sealing elements are secured against displacement in
the circumferential direction, lie as close as possible to each
other. In other words, the distance which exists in the radial
direction of the rotor between that surface of the rotor against
which the sealing element bears by centrifugal force and the
location of the security of the sealing element against
circumferential displacement should be as small as possible. This
means that sealing elements which bear against a contact surface of
a rotor blade should also be secured on their outer region against
displacement in the circumferential direction. In order to disclose
a construction which is as simple as possible for a circumferential
locking in this case, provision is made for a bolt-like blocking
element. On one side, the blocking element fits in an opening which
is provided in the sealing element. On the other side, the
bolt-like blocking element fits in a hole which is arranged in the
end face of a rotor blade root. The opening in the sealing element
in this case is comparatively close to that edge of the sealing
element which bears against the contact surface of the rotor. The
contact surface can preferably be a part of an underside of a
platform of the rotor blade. On account of the sealing element
bearing firmly against the contact surface by centrifugal force
action, only negligible, if any, relative movements occur between
sealing element and rotor blade root. The circumferential fixing of
the sealing element is therefore carried out on that component
against which the sealing element is supported during operation and
which therefore has an influence upon the position and movement of
the sealing element. By means of such an arrangement, wear on the
contact surface, on the sealing element and on the blocking element
can be reliably avoided.
[0010] The radial positioning of the blocking element with regard
to the rotor was subsequently selected so that its position is
located in a region which is movement-neutral relative to the rotor
blade so that compensation of the operation-induced movements in
the fixing point of the blocking element is not necessary. By using
a bolt-like blocking element, flexibility of the fixing can be
prevented.
[0011] A cooling medium, which is provided for cooling the rotor
disk and the rotor blade, is guided on the rotor section between
sealing element and end face of the rotor disk. The arrangement
which is proposed by the invention leads to the minimization of
leakages of cooling medium since by the use of a round opening in
the sealing element and use of the blocking bolt which is inserted
therein without clearance, a comparatively short leakage section,
or a leakage area of small dimension, is achieved. By reducing the
amount of cooling medium which is lost as leakage, an effiency
increase of the turbine can be achieved in principle.
[0012] On a rotor blade according to the invention, which comprises
at least a blade root, a platform and a curved blade airfoil,
provision is made for a projection which protrudes over the blade
root, wherein on the underside of the projection which faces the
blade root, provision is made for a contact surface, which faces
the blade root, for the plate-like sealing element. In order to
achieve a comparatively small distance between the contact surface
for the sealing element and a device for locking the sealing
element against movement in the circumferential direction,
provision is made for a blind hole for accommodating the blocking
element in the end face of the blade root, which hole is located
directly adjacent to the projection. With this, advantages similar
to the rotor section can be achieved.
[0013] The opening in the sealing element is of a keyhole-like
design and the blocking element is of a bolt-like design with a cam
arranged on its outer circumference. By means of the keyhole-like
opening, the bolt together with the cam can be inserted through the
opening of the sealing element, after which the blocking element is
rotated around its longitudinal axis in order to rotate the cam
into a gap between the blade root and the sealing element without
clearance.
[0014] In order to achieve a clearance-free fastening of the
sealing element, the bolt-like blocking element has a cam on its
outer circumference. The cam fits without clearance between
sidewalls--which lie directly opposite one another--of the sealing
element and of the rotor blade root. As a result of this, hammering
wear on the outer sealing element edge can be avoided.
[0015] Advantageous developments are disclosed in the dependent
claims.
[0016] The hole is arranged preferably close to, i.e. as seen
radially, and directly beneath the contact surface. Corresponding
to this, the opening of the sealing element, in which the bolt for
locking also fits, is also arranged comparatively close to that
edge of the sealing element which bears against the contact surface
of the rotor blade.
[0017] Particularly as a result of this, a positioning of the
bolt-like blocking element in a neutral region relative to the
rotor blade movement ensues.
[0018] In order to secure the blocking element itself against
rotation and therefore against loss from the rotor section, this
has a crenellation on the end face which can be bent into a bit
recess of the keyhole-like opening Created as a result of this is a
form-fit between crenellation and bit recess which after bending of
the crenellation reliably secures the blocking element against an
unwanted rotation inside the hole and inside the opening. An
unintentional loss of the blocking element can therefore be
avoided.
[0019] The crenellation is preferably part of an end-face ring of
the blocking element, as a result of which this can be produced
comparatively simply and inexpensively. In order to finally produce
the crenellation, provision is made in the encompassing rings for
two slots, between which the crenellation is arranged.
[0020] In an alternative advantageous development of the invention,
the blocking element can be secured against loss by means of a
Z-shaped sheet metal strip. To this end, the blocking element is
flattened along its longitudinal extent. The sheet metal strip,
which is still in the shape of an L before installation, is
inserted through the opening for this purpose and by its angled leg
is placed between sealing element and rotor blade root, after which
the bolt-like flattened blocking element is consequently inserted
into the opening and blind hole. The previously L-shaped sheet
metal strip is then brought into its Z-shape by bending round,
wherein this then secures the blocking element against loss.
[0021] A particularly simple removal of the blocking element is
achieved if--after the security against loss of the blocking
element has been removed--the blocking element has an end-face
opening for its removal. In the opening, provision can be made for
a thread, for example, in which a means for withdrawing the
blocking element from the opening and hole can be screwed. This
feature enables a particularly simple and quick removal of the
blocking element.
[0022] All the sealing elements, bearing against each other in the
circumferential direction, preferably form a sealing ring so that a
cooling medium can flow along between sealing ring and end face of
the blade root or end face of the rotor disk almost without loss.
The sealing elements in this case can also slightly overlap.
[0023] As a result of this, a particularly efficient guiding of
cooling medium along the end face of the blade root or blade disk
can be enabled.
[0024] If the hole is formed as a blind hole, this can be produced
comparatively simply.
[0025] According to a further development, the contact surface on
the underside of the projection of the rotor blade is formed at
least partially as the base of a slot which is open towards the
blade root. This prevents slipping of the sealing element in the
axial direction of the turbine rotor.
[0026] Overall, with the invention a construction which can be
designed in a straightforward and simple manner for the
circumferential fixing of sealing elements is disclosed, wherein
each sealing element is preferably secured by means of a blocking
element in each case. The blocking element, with correspondingly
manufactured cam, can be inserted like a key into a matching hole
in the sealing element and after reaching the axial end position
can be rotated by 180.degree. so that the cam secures the axial
fixing of the blocking bolt (key principle). In so doing, the
blocking element projects by its corresponding end into the
correspondingly dimensioned hole in the associated rotor blade root
so that displacement of the sealing element in the circumferential
direction is prevented. Securing the blocking bolt against unwanted
rotation and disengagement from the opening and from the blind hole
is carried out by means of a corresponding deformation of the
crenellation, which is arranged on the end face on the bolt, into
the bit recess--which is required on account of the cam--of the
opening so that rotation of the fixing bolt can be excluded. For
removal, the crenellation is to be levered out of the bit recess by
the use of a suitable driver tool. The blocking element can then be
rotated by 180.degree. and withdrawn.
[0027] The construction which is described by the invention has
high robustness in this case since this can be constructed so that
even with conservative consideration for the boundary conditions
the full circumferential forces of the sealing elements can be
reliably transferred. Flexibility of the fixing is not necessary.
Moreover, no expensively produced slots/pockets for accommodating a
bent-in locking plate are necessary, as a result of which the
arrangement is comparatively inexpensive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Further advantages and further features result from the
subsequent figure description. In the drawings:
[0029] FIG. 1 shows a partially perspective sectional view of a
rotor section,
[0030] FIG. 2 shows the detail A according to FIG. 1 in detail,
[0031] FIG. 3 shows an opening arranged in the sealing element for
accommodating a blocking element,
[0032] FIGS. 4, 5 show the blocking element in perspective
views,
[0033] FIG. 6 shows the perspective view of a part of a rotor blade
for a turbomachine,
[0034] FIG. 7 shows the plan view of a rotor arrangement according
to an alternative development,
[0035] FIG. 8 shows the alternative development of securing a
blocking element against axial displacement and
[0036] FIG. 9 shows a further blocking element in perspective
view.
DETAILED DESCRIPTION OF INVENTION
[0037] FIG. 1 shows in partially perspective, partially sectioned
view a rotor section 10 for the rotor of a turbomachine, which is
not additionally shown, which can be designed as a gas turbine. The
rotor section essentially comprises on the one hand a first rotor
disk 12 and a further rotor disk 14 which is adjacent thereto. The
rotor disks 12, 14 are interconnected in a form-fitting manner by
means of a Hirth toothing, which is not shown, for the transmission
of torque, and are clamped to each other via a tension bolt, which
is not additionally shown. The rotor section 10, alternatively to
the depicted representation, could also be formed from a single
piece in the form of a monoblock or from a singe rotor disk. On the
outer periphery of the rotor section 10, provision is made for a
plurality of rotor blade retaining grooves 16 which in each case
extend at least partially in the axial direction of the rotor and
of which only one is shown in section. The rotor blade retaining
groove 16 has a fir tree-shaped contour. Inserted into the rotor
blade retaining grooves 16 is a rotor blade 18 in each case, of
which that shown furthest on the right in FIG. 1 is to be seen in
section. The rotor blade 18 comprises a blade root 20 which is
formed to at least partially correspond to the contour of the rotor
blade retaining groove 16 in order to be retained by this in a
form-fitting manner in the radial direction. The rotor blade 18
comprises a platform 22 on which is arranged a blade airfoil, which
is not additionally shown. The platform 22, according to the
section according to FIG. 1, has an inwardly curved outer contour,
on the end of which provision is made for an outwardly projecting
seal point 24. In this respect, the platform 22 which is shown in
FIG. 1 also forms a sealing wing, which in the prior art is known
as an "angel wing", which projects over the end face 26 of the
blade root 20.
[0038] One end face 26 of the blade root 20 aligns with an end face
28 of the rotor disk 12. For each rotor blade, provision is made in
each case for a sealing element 30 on the rotor disk 12 on the end
face. By centrifugal force action, the sealing elements 30 by their
outer edge 32 bear against a contact surface 34, which contact
surface 34 is arranged on the underside of the platform 22 or of
the projection which protrudes over the blade root 20 on the end
face. The contact surface 34 accordingly points inwards. The
contact surface 34 could alternatively also be formed as the base
of a groove which is arranged on the underside of the platform. The
sealing elements 30 are of a strip-like or plate-like design and
furthermore comprise an inner edge 36 which fits in an outwardly
open annular groove 38.
[0039] The sealing elements 30 in this case have an inwardly
oriented hook 40 in their outer third on the surface facing the
rotor disk 12, which hook, in a way not shown, engages with a hook
which is arranged on the rotor disk 12 on the end face 28. As a
result of the hooking of the sealing elements 30 into the rotor
disk 12, displacement of the rotor blades 18 along the rotor blade
retaining groove 16 is reliably avoided so that the sealing
elements 30 bring about the axial locking of the relevant rotor
blade 18 in each case. Also, the sealing elements 30 serve for
guiding a cooling medium, preferably cooling air, along the end
face 28 of the rotor disk 12 and end face 26 of the blade root
20.
[0040] In order to prevent displacement of the sealing elements 30
in the circumferential direction, provision is made in the region
of the outer edge 32 of the sealing elements 30 for an opening 44
in each case. The opening 44, a blocking element 46 which fits
therein, and a part of the blade root 20, are shown in detail in
FIG. 2. FIG. 3 shows the opening 44 in a perspective view. The
opening 44 is of a keyhole-like design with a circular opening
section, adjoining which, towards the bottom in FIG. 3, is a
comparatively short and a comparatively wide bit recess 47.
[0041] The blocking element 46 which is shown perspectively in FIG.
4 and in FIG. 5 has a cam 50 on its outer circumference. The cam 50
is provided rather on the end side, i.e. on an end-face first end
48 of the blocking element 46 and extends along the circumference
over an angular length of about 20.degree.. The angular length of
the cam 50 corresponds in this case to the width of the bit recess
47 so that the blocking element 46 can be inserted through the
opening 44 into the sealing element 30. The blocking element 46,
moreover, on its second end-face end has a ring 52 in which two
slots 54 are provided so that a part of the ring 52 is foamed as a
crenellation 56 or tooth. The slots 54 in this case are arranged on
that part of the circumference which lies opposite the ends of the
cam 50. In this respect, the crenellation 56 and the cam are at
least approximately of equal width. The free end of the
crenellation 56 is constructed with a point in this case in order
to simplify removal.
[0042] The blocking element 46 is shown in its end position in FIG.
2. For installing the blocking element 46 in the opening 44, the
blocking element is to be oriented so that the cam 50 can be
inserted through the bit recess 47. After inserting the blocking
element 46 in the opening 44, this is rotated around its
longitudinal axis by 180.degree. until the crenellation 56 which is
arranged on its second end is in the region of the bit recess 47.
Using a suitable tool, the crenellation 56 can be bent into the bit
recess 47 so that the blocking element 46 is secured against
rotation as a result. After inserting the blocking element 46, its
end 48 provided with the cam 50 projects into a hole 58 which is
arranged on the end face 26 of the blade root 20. The hole 58 in
this case is formed as a blind hole in which the end 48 of the
blocking element 46 fits with clearance.
[0043] The cam 50 correspondingly engages in an axial gap which
exists between the end face 26 of the blade root 20 and the sealing
element 30. To this end, the sealing element 30 is of a sleeve-like
design in the region of the opening 44.
[0044] For removal of the rotor blade 18, the crenellation 56 is
bent up, as a result of which the form-fit with the bit recess 47
is released. After this, the blocking element 46 can be rotated by
180.degree. so that the cam 50 is located in the region of the bit
recess 47. With a suitable tool, the blocking element 46 can then
be removed from the opening 44, after which the sealing element 30
can then be displaced in the circumferential direction. As a result
of displacing the sealing element 30 in the circumferential
direction, the hooking of the sealing element into the rotor disk
can be released, therefore the sealing element can be removed from
the rotor section 10. The rotor blade 18 can then be removed from
the rotor section 10 by axial displacement along the retaining
groove 16.
[0045] The blind hole 58 which is arranged in the rotor blade root
20 is arranged comparatively close to the contact surface 34 in
this case.
[0046] FIG. 6 shows the turbine blade 18 in a perspective view,
wherein the blade airfoil 60 of the turbine blade 18 is shown only
close to the platform, however. Clearly emerging from FIG. 6 is the
fact that the blind hole is arranged comparatively close, i.e.
directly adjacent, to the contact surface 34. Therefore, the
contact surface 34 for the sealing element 30 and its means for
preventing movement in the circumferential direction are arranged
comparatively close to one another. As a result of the local
proximity of both functional means, a particularly secure and
reliable displacement blocking can be disclosed, which, moreover,
is particularly free of wear since almost no rubbing relative
movements arise.
[0047] FIG. 7 shows the sealing elements 30, adjacent to each other
in the circumferential direction, which before their locking by
means of the blocking element are movable in relation to each other
in order to enable the installation of a sealing ring which is
closed per se. To this end, the edges of the sealing elements which
point towards an adjacent sealing element, have in each case only
half the material thickness of the sealing element wall so that the
sealing elements are formed with overlapping effect in these
regions. Instead of a simple overlapping, provision may also be
made for tongue-in-groove overlapping.
[0048] The alternative development of the circumferential locking
which is shown in FIG. 7 differs from that shown in FIGS. 1 to 6
with regard to the additional blocking element 62 and its security
against loss from the opening 44 and from the hole 58. The
additional blocking element 62 which is shown in FIG. 7 is shown
perspectively in FIG. 9. The additional blocking element 62
according to the alternative development is also of a bolt-like
design with two different diameters. Along its longitudinal extent,
the blocking element 62, however, is formed with a flattened
section so that a locking plate can bear against the flat 64. The
securing of the blocking element 62 is shown in FIG. 8, wherein
FIG. 8 shows the same detail as the detail A which is shown in FIG.
2. Also in this case, identical components are provided with the
same designations. After installing the rotor blade 18 in the
retaining groove 16 and the subsequent installing of the sealing
element 30, an initially L-shaped locking plate 66a is inserted
into the opening 44, the shorter leg of which engages in a gap
between the end face 26 of the blade root 20 and sealing element
30. The blocking element 62 is then positioned on the locking plate
66 by its flat 64. After this, the blocking element 62 is inserted
into the opening 44 until it engages by its end 48 in the blind
hole 58. Therefore, with a suitable means the previously L-shaped
locking plate 66a, as seen in cross section, is bent round so that
this is Z-shaped in cross section. As a result of the Z-shape of
the locking plate 66, this blocks an axial displacement of the
blocking element 62. As a result of this, the locking of the
sealing element 30 in the circumferential direction cannot be
inadvertently released.
[0049] Overall, the invention refers to a rotor section 10 for a
rotor of a gas turbine, to a rotor blade 18 and to a blocking
element 46, 62. The rotor section 10 comprises a rotor disk 12 with
rotor blades 18 inserted in retaining grooves 16 thereupon, the
rotor blades being secured against displacement along the retaining
grooves 16 by means of a sealing element 30 which is arranged on
the end face. In order to disclose a reliable construction which
can be designed in a straightforward and simple manner for the
circumferential fixing of the sealing element 30, the invention
proposes that each sealing element 30 is secured by means of a
blocking element 46, 62 in each case which in this case engages in
a hole 58 which is arranged in the rotor blade root 20 on the end
face.
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